1. Technical Field of the Invention
This invention generally relates to a presser assembly for a blanking operation, and, more particularly, to a presser assembly for supporting and/or advancing blanking scrap, such as paper, paperboard, or carton blanking scrap, during a blanking operation.
2. Description of Related Art
In the manufacture of cartons and paper products, small sheets of material are typically cut out of larger sheets. These smaller sheets are known as blanks that, in turn, may be further formed into various shapes, such as, by way of example, into boxes. The blanks are formed during a process known as a blanking operation. In a blanking operation, the blanks are cut, but not removed, from the large sheet of paper, paperboard, or carton material. After the blanks have been cut, the sheet is positioned over a frame for support. The frame typically includes large openings that correspond in size and in position to the blanks previously cut. Below the frame is typically a mechanism for stacking the blanks. In order to knock the blanks from the sheet of material and hold the scrap material, an assembly known in the art as a presser assembly is used. The presser assembly includes a support tool having a presser member and a presser rail depending therefrom. The presser rail is biased away from the support tool. As the support tool is lowered, the presser rail engages the sheet of material such that the sheet of material is secured between the presser rail and the frame. The support tool continues to be lowered such that the presser member engages the blanks and knocks the blank out of the sheet of material. The carton blanks fall onto a stacking mechanism wherein the blanks are stacked.
If the presser rail does not adequately hold the blanking scrap, the scrap may fall onto the stacking mechanism. A carton blanking scrap in the stacking mechanism may jam the mechanism thereby causing downtime and expense. In order to securely hold the carton blank scrap, one conventional presser assembly provides presser rails interconnected to the support tool by a plurality of guide cylinders. Each guide cylinder biases the presser rail away from the support tool. This gives the presser rail a certain amount of flexibility when engaging the carton blanking scrap. However, even with this limited flexibility, present day presser rails and assemblies have been found to be inadequate and require substantial assembly and various parts. An example of such a presser assembly is described in U.S. Pat. No. 5,529,565, the subject matter of which is incorporated herein in its entirety by reference.
The prior art fails to provide a presser assembly that offers a simple configuration, requires low cost to manufacture, is easy to assemble, and that is easily and efficiently mountable to a backer board of a blanking device.
It is a purpose of the present invention to solve the above-mentioned problems.
To achieve the above purpose, the present invention provides a presser assembly for supporting blanking scrap during a blanking operation. The presser assembly includes: a support rail; a presser rail connected to the support rail; and a connecting rail connecting the presser rail to the support rail and being adapted to pivot with respect to at least one of the support rail and the presser rail through a predetermined pivot angle range. The pivot angle range is for changing a distance between the support rail and the presser rail to thereby selectively affect a folding and an unfolding of the presser assembly during the blanking operation.
The present invention further encompasses a die cutting or blanking press that includes a presser assembly for supporting blanking scrap during a blanking operation. The assembly includes: a support rail; a presser rail adapted to be connected to the support rail; and a connecting rail adapted to connect the presser rail to the support rail and adapted to pivot with respect to at least one of the support rail and the presser rail in an assembled state of the presser assembly. The pivoting is through a predetermined pivot angle range for changing a distance between the support rail and the presser rail thereby selectively effecting a folding and an unfolding of the presser assembly during the blanking operation. The assembly is operatively mounted on the die cutting or blanking press to support and/or advance a blank sheet or blanking scrap in a blanking operation.
Moreover, the present invention provides a presser assembly for supporting blanking scrap during a blanking operation, where the presser assembly includes: a support means; a presser means connected to the support means and supported thereby; and a connecting means for connecting the presser means to the support means and being adapted to pivot with respect to the presser means through a predetermined pivot angle range for changing a distance between the presser means and the support means thereby selectively affecting a folding and an unfolding of the presser assembly during the blanking operation.
Additionally, the present invention provides a method of using a presser assembly as described above. The method comprises the steps of: pivoting the connecting rail or means with respect to at least one of the support rail or means and the presser rail or means for reducing an angle defined therebetween, thereby folding the presser assembly for reducing a distance between the presser rail and the support rail; and pivoting the connecting rail or means with respect to at least one of the support rail or means and the presser rail or means for increasing an angle defined therebetween, thereby unfolding the presser assembly for increasing a distance between the presser rail or means and the support rail or means.
The present invention also provides a method of forming blanks from a blanking sheet, where the method includes support and/or advancing a blanking sheet and a blanking press through the use of a presser assembly as described above. According to a first embodiment of such a method, a presser assembly according to an embodiment of the present invention is used to hold, support, or secure a blanking sheet in a blanking press during a die cutting or blank forming operation. According to such an embodiment, the presser rail or presser means of the assembly contacts and biases the blanking sheet against a press support or counterplate positioned on a side of the blanking sheet which is opposite the side contacted by the presser rail or presser means, during a die cutting or blank forming operation. The blank sheet is thereby supported and stabilized during the die cutting operation to facilitate efficient and clean blank formation.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.